body{
    padding: 10vh 10vw;
}
h1{
    font-size: 3em;
    padding-left: 16vh;
    margin-bottom: .8em;
}
h2{
    font-size: 2em;
    margin-bottom: 1.4em;
}
p{
    font-size: 1.4em;
    padding-left: 1vh;
    font-weight: 300;
    line-height: 1.6rem；
    max-width 600px;
   }
a{
    display: inline-block;
    position: relative;
    color: rgb(17, 17, 17);
    text-decoration: none;
    margin: .4em 1.2em .6em .4em;
    max-width: 100px;
}
span{
    display: inline-block;
}
a:after{
   content: '';
   position: absolute;
   z-index: -1;

   top: 60%;
   left: -0.4em;
   right: -0.4em;
   bottom: 0;

   border-radius: .4em;

   transition:top 200ms cubic-bezier(0, 0.8, 0.13, 1) ;
   background-color:rgba(30, 144, 255, .4);
}
a:hover:after{
    top: 10%
}